- specify evaluation order of floating-point expressions as
  discussed
- specify floating point conversion rounding as discussed
- slightly reformatted section on conversions to make it
  more readable (hopefully)
- fixed production for interpreted_string_lit - components
  were not properly tagged before because of """ instead of `"`

R=go-dev
DELTA=83  (41 added, 11 deleted, 31 changed)
OCL=35864
CL=35885